Adherence concepts for non-woven absorbable felt buttresses

ABSTRACT

A loading unit for use with a surgical stapling apparatus including a tool assembly and a surgical buttress. The tool assembly includes: a cartridge assembly including a staple cartridge having a tissue facing surface, staple retaining pockets having a plurality of surgical fasteners therein, and a knife slot; and an anvil assembly including an anvil plate having a tissue facing surface defining staple forming pockets and a knife slot. The surgical buttress is attached to the tissue facing surface of at least one of the cartridge assembly or the anvil assembly, and conforms to the tissue facing surface such that the surgical buttress is deformed locally into the staple retaining pockets and the knife slot of the cartridge assembly or the staple forming pockets and the knife slot of the anvil assembly to which the surgical buttress is attached.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of U.S. patent application Ser.No. 14/172,036, filed on Feb. 4, 2014, which claims the benefit of, andpriority to, U.S. Provisional Application Ser. No. 61/770,855, filed onFeb. 28, 2013 the entire disclosure of each of which is incorporated byreference herein.

The present application relates to U.S. patent application Ser. No.13/729,144, filed on Dec. 28, 2012, now U.S. Pat. No. 8,631,989, whichis a Continuation Application which claims the benefit of and priorityto U.S. application Ser. No. 13/097,194, filed on Apr. 29, 2011, nowU.S. Pat. No. 8,365,972, which is a Continuation-In-Part Applicationwhich claims the benefit of and priority to U.S. application Ser. No.12/414,943, filed on Mar. 31, 2009, now U.S. Pat. No. 8,011,550, theentire content of each of which is incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to a surgical apparatus having a buttressmaterial incorporated therewith. More particularly, the presentdisclosure relates to a surgical stapling apparatus including adetachable surgical buttress and/or an endoscopic surgical staplingapparatus that includes a detachable surgical buttress.

Background of Related Art

Surgical devices for grasping or clamping tissue between opposing jawstructure and then joining tissue by surgical fasteners are well knownin the art. In some instruments a knife is provided to cut the tissuewhich has been joined by the fasteners. The fasteners are typically inthe form of surgical staples but two-part polymeric fasteners can alsobe utilized.

Instruments for this purpose can include two elongated jaw members whichare respectively used to capture or clamp tissue. In certain surgicalstaplers, one of the jaw members carries a staple cartridge which housesa plurality of staples arranged in at least two lateral rows while theother jaw member has an anvil that defines a surface for forming thestaple legs as the staples are driven from the staple cartridge. Thestapling operation is effected by cam members that travel longitudinallythrough the staple cartridge, with the cam members acting upon staplepushers to sequentially eject the staples from the staple cartridge. Aknife can travel between the staple rows to longitudinally cut and/oropen the stapled tissue between the rows of staples. Such instrumentsare disclosed, for example, in U.S. Pat. Nos. 3,079,606 and 3,490,675.

Another stapler disclosed in U.S. Pat. No. 3,499,591 also applies adouble row of staples on each side of the incision. This patentdiscloses a surgical stapler that has a disposable loading unit in whicha cam member moves through an elongate guide path between two sets ofstaggered staple carrying grooves. Staple drive members are locatedwithin the grooves and are positioned in such a manner so as to becontacted by the longitudinally moving cam member to effect ejection ofthe staples from the staple cartridge of the disposable loading unit.Other examples of such staplers are disclosed in U.S. Pat. Nos.4,429,695 and 5,065,929.

Each of the instruments described above is designed for use in surgicalprocedures in which surgeons have direct manual access to the operativesite. However, in endoscopic or laparoscopic procedures, surgery isperformed through a small incision or through a narrow cannula insertedthrough small entrance wounds in the skin. In order to address thespecific needs of endoscopic and/or laparoscopic surgical procedures,endoscopic surgical stapling devices have been developed and aredisclosed in, for example, U.S. Pat. No. 5,040,715 (Green, et al.); U.S.Pat. No. 5,307,976 (Olson, et al.); U.S. Pat. No. 5,312,023 (Green, etal.); U.S. Pat. No. 5,318,221 (Green, et al.); U.S. Pat. No. 5,326,013(Green, et al.); U.S. Pat. No. 5,332,142 (Robinson, et al.); and U.S.Pat. No. 6,241,139 (Milliman et al.), the entire contents of each ofwhich are hereby incorporated herein by reference.

Tyco Healthcare Group, LP, the assignee of the present application, hasmanufactured and marketed endoscopic stapling instruments, such as theMultifire ENDO GIA™. 30 and Multifire ENDO GIA™. 60 instruments, for anumber of years. These instruments include a surgical stapling apparatusand a loading unit. Typically, the loading unit is attached to theapparatus immediately prior to surgery. After use, the loading unit canbe removed from the apparatus and a new loading unit can be fastened tothe apparatus to perform additional stapling and/or cutting operations.These instruments have provided significant clinical benefits.Nonetheless, improvements to these instruments are still desirable.

When stapling relatively thin or fragile tissues, it is important toeffectively seal the staple line against air or fluid leakage.Additionally, it is often necessary to reinforce the staple line againstthe tissue to prevent tears in the tissue or pulling of the staplesthrough the tissue. One method of preventing tears or pull throughinvolves the placement of a biocompatible fabric reinforcing material,or “buttress” material, between the staple and the underlying tissue. Inthis method, a layer of buttress material is placed against the tissueand the tissue is stapled in conventional manner. In another method, thebuttress material is positioned on the stapling instrument itself priorto stapling the tissue. An exemplary example of this is disclosed inU.S. Pat. No. 5,542,594 to McKean et al., the entire content of which isincorporated herein by reference. In McKean et al., a tube of buttressmaterial is slipped over the jaw of the stapler. The stapler is thenactuated to staple the subject tissue and secure the buttress materialbetween the tissue and staple line to reinforce the tissue and stapleline.

Buttress materials which are either pre-loaded or are an after-marketadd-on, for endomechanical or open mechanical surgical staplingapparatus, may shift in position relative to a stapler reload cartridgeassembly and anvil assembly to which they are attached during graspingand manipulation of tissue by the surgical stapling apparatus. If theshifting of the buttress material is pronounced and is not corrected bythe surgeon before firing the surgical stapling apparatus, then staplesmay form outside the perimeter or width of the buttress material therebyreducing the benefits of having the entire staple line reinforced by thebuttress material.

Accordingly, a need exists to systems and methods for securing abuttress material to the tissue contacting/facing surface of a cartridgeassembly and/or anvil assembly of a surgical stapling apparatus, wherebythe buttress material remains secured in place over top of the stapleretaining slots and/or staple forming pockets, along an entire lengththereof.

Additionally, a need exists to design or modify the mechanical andphysical properties of the buttress material to reduce the impact ofmaterial shifting on the stapler reload cartridge assembly and anvilassembly.

SUMMARY

In accordance with the present disclosure a surgical stapling apparatusis provided including a housing; a handle supported by the housing; anelongated body extending distally from the housing; and a tool assemblyat the distal end of the elongated body. The tool assembly has acartridge assembly including a staple cartridge having a tissue facingsurface, a plurality of staple retaining pockets and a knife slot formedin the tissue facing surface thereof. The tool assembly also has aplurality of surgical fasteners loaded one each in the staple retainingpockets. The tool assembly additionally has an anvil assembly injuxtaposed relation to the cartridge assembly, the anvil assemblyincluding an anvil plate having a tissue facing surface defining aplurality of staple forming pockets and a knife slot therein, at leastone of the cartridge assembly or the anvil assembly being movable inrelation to the other of the cartridge assembly and the anvil assembly.

The surgical stapling apparatus further includes a surgical buttressreleasably secured to a tissue contacting surface of at least one of theanvil plate and the staple cartridge, wherein each surgical buttress issecured to the at least one of the anvil assembly and the cartridgeassembly by at least one anchor; a release assembly associated with theat least one of the anvil assembly and the cartridge assembly; and adrive assembly slidably translatable through the tool assembly from aproximal position to a distal position, wherein the drive assemblyactuates the release assembly to thereby release the anchor and to freethe surgical buttress from the at least one of the anvil assembly andcartridge assembly.

The release assembly may grip the at least one anchor prior to anactuation of the drive assembly.

The at least one of the anvil assembly and the cartridge assembly maydefine a side slot for receiving an end of the at least one anchortherein.

The release assembly may include a first bar extending across thelongitudinal slot prior to an actuation of the drive assembly; and asecond bar, connected to and actuatable by the first bar, having an endextending at least partially into the side slot, prior to an actuationof the drive assembly.

In use, as the drive assembly is advanced to the distal position, thedrive assembly may actuate the first bar of the release assembly whichin turn may actuate the second bar of the release assembly to releasethe anchor disposed within the side slot.

Each of the anvil assembly and the cartridge assembly may include arelease assembly. Each of the anvil assembly and the cartridge assemblymay define a side slot for receiving the anchor of each surgicalbuttress.

Each release assembly may include a first bar extending across thelongitudinal slot prior to an actuation of the drive assembly; and asecond bar, connected to and actuatable by the first bar, having an endextending at least partially into the side slot, prior to an actuationof the drive assembly. In use, as the drive assembly is advanced to thedistal position, the drive assembly may actuate the first bar of eachrelease assembly which in turn may actuate the second bar of eachrelease assembly to release the anchor disposed within the each sideslot.

At least one of the anvil assembly and the cartridge assembly mayinclude a constricting, open-ended, side slot configured to grip an endof the anchor, and wherein the release assembly may push the end of theanchor out of the side slot, upon a distal advancement of the driveassembly.

The release assembly may include a pusher that is in operativeassociation with the side slot retaining the end of the anchor. Thepusher may be actuatable by a distally advancing drive member to pushthe end of the anchor out of the side slot.

The pusher of the release assembly may be one of pivotally connected toand slidably supported in at least one of the anvil assembly and thecartridge assembly.

The anchor may be a suture engaging the surgical buttress and the atleast one of the cartridge assembly and the anvil assembly. The anchormay be an extension of the surgical buttress and engages the at leastone of the cartridge assembly and the anvil assembly.

According to another aspect of the present application, a loading unitfor use with a surgical stapling apparatus is provided and includes atool assembly having a cartridge assembly including a cartridge having aplurality of surgical fasteners therein, and an anvil assembly, at leastone of the cartridge assembly and the anvil assembly being movable inrelation to the other of the cartridge assembly and anvil assembly,wherein the anvil assembly includes an anvil plate and, wherein each ofthe anvil plate and the staple cartridge define an elongate longitudinalslot; a surgical buttress releasably secured to a tissue contactingsurface of at least one of the anvil plate and the staple cartridge,wherein each surgical buttress is secured to the at least one of theanvil assembly and the cartridge assembly by at least one anchor; arelease assembly associated with the at least one of the anvil assemblyand the cartridge assembly; and a drive assembly slidably translatablethrough the tool assembly from a proximal position to a distal position,the drive assembly actuating the release assembly to thereby release theanchor to free the surgical buttress from the at least one of the anvilassembly and cartridge assembly.

The release assembly may grip the at least one anchor prior to anactuation of the drive assembly.

At least one of the anvil assembly and the cartridge assembly may definea side slot for receiving an end of the at least one anchor therein.

The release assembly may include a first bar extending across thelongitudinal slot prior to an actuation of the drive assembly; and asecond bar, connected to and actuatable by the first bar, having an endextending at least partially into the side slot, prior to an actuationof the drive assembly.

In use, as the drive assembly is advanced to the distal position, driveassembly actuates the first bar of the release assembly which in turnactuates the second bar of the release assembly to release the grip onthe end of the at least one anchor disposed within the side slot.

Each of the anvil assembly and the cartridge assembly may include arelease assembly.

At least one of the anvil assembly and the cartridge assembly mayinclude a constricting, open-ended, side slot configured to grip an endof the anchor disposed therein, and wherein the release assembly maypush the end of the anchor out of the side slot, upon a distaladvancement of the drive assembly.

According to a further aspect of the present disclosure, a surgicalstapling apparatus is provided and includes a housing; a handlesupported by the housing; an elongated body extending distally from thehousing; and a tool assembly at the distal end of the elongated body.The tool assembly includes a cartridge assembly including a cartridgehaving a plurality of surgical fasteners therein, and an anvil assemblyin juxtaposed relation to the cartridge assembly, at least one of thecartridge assembly and anvil assembly being movable in relation to theother of the cartridge assembly and anvil assembly. The anvil assemblyincludes an anvil plate defining a pair of opposed distal side slots forreceiving an end of an anchor and a pair of opposed proximal side slotsfor receiving an end of an anchor. The anvil plate includes at least oneof the following: at least one of the pair of distal side slots iskeyhole-shaped; and at least one of the pair of proximal side slots iskeyhole-shaped. The surgical stapling apparatus further includes asurgical buttress releasably secured to a tissue contacting surface ofat least one of the anvil plate and the staple cartridge, wherein eachsurgical buttress is secured to the at least one of the anvil assemblyand the cartridge assembly by at least one anchor; a release assemblyassociated with the at least one of the anvil assembly and the cartridgeassembly; and a drive assembly slidably translatable through the toolassembly from a proximal position to a distal position, the driveassembly actuating the release assembly to thereby release the anchorand to free the surgical buttress from the at least one of the anvilassembly and cartridge assembly.

According to yet another aspect of the present disclosure, a loadingunit for use with a surgical stapling apparatus is provided. The loadingunit comprises a tool assembly having a cartridge assembly including acartridge having a plurality of surgical fasteners therein, and an anvilassembly in juxtaposed relation to the cartridge assembly, at least oneof the cartridge assembly and anvil assembly being movable in relationto the other of the cartridge assembly and anvil assembly. The anvilassembly includes an anvil plate defining a pair of opposed distal sideslots for receiving an end of an anchor and a pair of opposed proximalside slots for receiving an end of an anchor. The anvil plate includesat least one of the following: at least one of the pair of distal sideslots is keyhole-shaped; and at least one of the pair of proximal sideslots is keyhole-shaped. The loading unit further includes a surgicalbuttress releasably secured to a tissue contacting surface of at leastone of the anvil plate and the staple cartridge, wherein each surgicalbuttress is secured to the at least one of the anvil assembly and thecartridge assembly by at least one anchor; a release assembly associatedwith the at least one of the anvil assembly and the cartridge assembly;and a drive assembly slidably translatable through the tool assemblyfrom a proximal position to a distal position, the drive assemblyactuating the release assembly to thereby release the anchor to free thesurgical buttress from the at least one of the anvil assembly andcartridge assembly.

Each of the anvil plate and the staple cartridge may define an elongatelongitudinal slot.

The cartridge assembly may define at least one side slot for receivingan end of the at least one anchor therein.

Each of the anvil assembly and the cartridge assembly may include arelease assembly.

Each of the anvil assembly and the cartridge assembly may define a sideslot for receiving the anchor associated with each surgical buttress.

At least one of the anvil assembly and the cartridge assembly mayinclude a keyhole-shaped side slot.

The anchor may be a suture that is in engagement with the surgicalbuttress and the at least one of the cartridge assembly and the anvilassembly.

Additional advantages will become apparent from the description whichfollows, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be further described with reference to theaccompanying drawings, wherein like reference numerals refer to likeparts in the several views, and wherein:

FIG. 1 is a perspective view of a surgical stapling apparatus accordingto an embodiment of the present disclosure;

FIG. 2 is a top, perspective view, with parts separated, of a distal endof a loading unit of the surgical stapling apparatus of FIG. 1;

FIG. 2A is an enlarged perspective view of a distal end of an anvilassembly of the loading unit illustrating a surgical anvil buttressoperatively secured to a tissue contacting surface thereof;

FIG. 2B is an enlarged perspective view of a cartridge assembly of theloading unit illustrating a surgical cartridge buttress secured to atissue contacting surface thereof;

FIG. 3 is a top, perspective view of a distal end of an anvil assemblyof the loading unit including a suture release assembly according to anembodiment of the present disclosure, shown in an open configuration;

FIG. 4 is a top, perspective view of the anvil assembly of FIG. 3,illustrating the parts of the suture release assembly thereof separated;

FIG. 5 is a bottom, perspective view of the anvil assembly of FIGS. 3and 4;

FIG. 6 is a top, plan view of the anvil assembly of FIGS. 3-5,illustrating the suture release assembly thereof in the closedconfiguration;

FIG. 7 is a top, plan view of the anvil assembly of FIG. 6, with aretainer removed therefrom;

FIG. 8 is a top, plan view of the anvil assembly of FIGS. 3-7,illustrating the suture release assembly thereof in the openconfiguration;

FIG. 9 is a top, plan view of the anvil assembly of FIG. 8, with aretainer removed therefrom;

FIG. 10 is a top, perspective view of a distal end of a cartridgeassembly of the DLU including a suture release assembly according to anembodiment of the present disclosure;

FIG. 11 is a top, perspective view of the cartridge assembly of FIG. 10,illustrating the parts of the suture release assembly thereof separated;

FIG. 12 is a bottom, perspective view of a distal end of the cartridgeassembly of FIGS. 10 and 11;

FIG. 13 is a top, plan view of the cartridge assembly of FIGS. 10-12,illustrating the suture release assembly thereof in the closedconfiguration;

FIG. 14 is a top, plan view of the cartridge assembly of FIGS. 10-13,illustrating the suture release assembly thereof in the openconfiguration;

FIG. 15 is a perspective view of a distal end of a loading unitincluding suture release assemblies according to another embodiment ofthe present disclosure;

FIG. 16 is an enlarged view of the indicated area of detail of FIG. 15;

FIG. 17 is a top, perspective view of a distal end of an anvil assembly(with an anvil cover removed), illustrating a suture release assemblythereof in an actuated configuration;

FIG. 18 is a top, perspective view of the distal end of the anvilassembly of FIG. 17, illustrating the parts of the suture releaseassembly thereof separated;

FIG. 19 is a top, plan view of the anvil assembly of FIGS. 17 and 18,illustrating the suture release assembly thereof in an unactuatedconfiguration;

FIG. 20 is a top, plan view of the anvil assembly of FIGS. 17-19,illustrating the suture release assembly thereof in an actuatedconfiguration;

FIG. 21 is a bottom, perspective view of a distal end of a cartridgeassembly of the DLU of FIG. 15, illustrating a suture release assemblythereof separated therefrom;

FIG. 22 is a top, perspective view of the suture release assembly ofFIG. 21;

FIG. 23 is a bottom, perspective view, with parts separated, of thesuture release assembly of FIGS. 21 and 22;

FIG. 24 is a top, plan view of the suture release assembly of FIGS.21-23, illustrating the suture release assembly thereof in an unactuatedconfiguration;

FIG. 25 is a top, plan view of the suture release assembly of FIGS.21-24, illustrating the suture release assembly thereof in an actuatedconfiguration;

FIG. 26 is a top, plan view of a distal end of an anvil assembly of aloading unit including a suture release assembly according to yetanother embodiment of the present disclosure;

FIG. 27 is a top, perspective view, with parts separated, of the distalend of the anvil assembly of FIG. 26;

FIG. 28 is a top, plan view of the distal end of the anvil assembly ofFIGS. 26 and 27, illustrating the suture release assembly thereof in anunactuated configuration;

FIG. 29 is a top, plan view of the distal end of the anvil assembly ofFIGS. 26-28, illustrating the suture release assembly thereof in anactuated configuration;

FIG. 30 is a top, plan view of a distal end of an anvil assembly of aloading unit including a suture release assembly according to stillanother embodiment of the present disclosure, illustrating the suturerelease assembly thereof in an unactuated configuration;

FIG. 31 is a top, plan view of the distal end of the anvil assembly ofFIG. 30, illustrating the suture release assembly thereof in an actuatedconfiguration;

FIG. 32 is a top, perspective view of a distal end of a cartridgeassembly of a loading unit including a suture release assembly accordingto a further embodiment of the present disclosure;

FIG. 33 is a top, perspective view of the suture release assembly ofFIG. 32;

FIG. 34 is a bottom, perspective view of the suture release assembly ofFIGS. 32 and 33;

FIG. 35 is a bottom, perspective view, with parts separated, of thesuture release assembly of FIGS. 32-34;

FIG. 36 is a top, perspective view, with parts separated, of the suturerelease assembly of FIGS. 32-35;

FIG. 37 is a top, plan view of the suture release assembly of FIGS.32-36, illustrating the suture release assembly in an unactuatedconfiguration;

FIG. 38 is a top, plan view of the suture release assembly of FIGS.32-37, illustrating the suture release assembly in an actuatedconfiguration;

FIG. 39 is a rear, perspective view, with parts separated of an anvilassembly according to another embodiment of the present disclosure;

FIG. 40 is a top, plan view of a distal end of the anvil assembly ofFIG. 39 (with an anvil cover removed therefrom), illustrating a suturerelease assembly according to another embodiment of the presentdisclosure;

FIG. 41 is a bottom, plan view of an anvil plate of the anvil assemblyof FIG. 39;

FIG. 42 is a top, plan view of the anvil plate of FIG. 41;

FIG. 43 is an enlarged view of the indicated area of detail of FIG. 42;

FIG. 44 is an enlarged view of the indicated area of detail of FIG. 42;

FIG. 45 is a top, plan view of an anvil cover of the anvil assembly ofFIG. 39;

FIG. 46 is an enlarged view of the indicated area of detail of FIG. 45;

FIG. 47 is an enlarged view of the indicated area of detail of FIG. 45showing a different embodiment of a suture receiving slot;

FIG. 48 is an enlarged view of the indicated area of detail of FIG. 45showing a different embodiment of a suture receiving slot;

FIG. 49 is an enlarged view of the indicated area of detail of FIG. 45showing a different embodiment of a suture receiving slot;

FIG. 50 is a cross-sectional view of the indicated area of detail ofFIG. 45, as taken through line 50-50 of FIG. 49;

FIG. 51 is a transverse, cross-sectional schematic illustration of acartridge assembly including a surgical buttress overlying a tissuecontacting/facing surface thereof; and

FIG. 52 is a transverse, cross-sectional schematic illustration of ananvil assembly including a surgical buttress overlying a tissuecontacting/facing surface thereof.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed surgical stapling apparatus andloading unit will now be described in detail with reference to thedrawings, in which like reference numerals designate identical orcorresponding elements in each of the several views.

In the drawings and in the description that follows, the term“proximal”, as is traditional, will refer to the end of the staplingapparatus which is closest to the operator, while the term “distal” willrefer to the end of the apparatus which is furthest from the operator.

FIG. 1 shows a surgical apparatus, e.g., surgical stapling apparatus,generally referred to as 10. In the interest of brevity, this disclosurewill focus primarily on to the tool assembly of the surgical staplingapparatus 10. A detailed discussion of the remaining components andmethod of use of surgical stapling apparatus 10 is disclosed in U.S.Pat. No. 6,241,139, the disclosure of which is hereby incorporated byreference herein.

Surgical stapling apparatus 10 is an endoscopic apparatus and includes ahandle assembly 12 and an elongated body 14 extending from handleassembly 12. A loading unit 16 is releasably secured to the distal endof elongated body 14. Furthermore, the present disclosure contemplatessurgical stapling apparatus that have a replaceable cartridge that isreceived in the jaws of the apparatus.

Loading unit 16 includes a tool assembly 17 having a cartridge assembly18 housing a plurality of surgical fasteners or staples 84 (see FIG. 2)and an anvil assembly 20 secured in juxtaposed relation relative tocartridge assembly 18, wherein anvil assembly 20 and cartridge assembly18 are moveable to or away from one another to close or open toolassembly 17. As shown herein, loading unit 16 is configured to apply six(6) linear rows of staples, in loading units measuring from about 30 mmto about 60 mm in length. Loading units for applying any number of rowsof staples, having staple pockets arranged in various patterns and/orloading units and end effectors having any other lengths, e.g., 45 mm,are also envisioned. Handle assembly 12 includes a stationary handlemember 22, a movable handle member 24, and a barrel portion 26.

A rotatable member 28 is mounted on the forward end of barrel portion 26to facilitate rotation of elongated body 14 and attached loading unit 16with respect to handle assembly 12. An articulation lever 30 is alsomounted on the forward end of barrel portion 26 adjacent rotatablemember 28 to facilitate articulation of tool assembly 17. Preferably, apair of knobs 32 are movably positioned along barrel portion 26. Knobs32 are advanced distally to approximate or close cartridge and/or anvilassembly 18, 20, and retracted proximally to unapproximate or opencartridge and/or anvil assembly 18, 20.

Loading unit 16 is desirably selectively removably couplable toelongated body 14. Loading unit 16 includes a housing portion 36 havinga proximal end adapted to releasably engage the distal end of elongatedbody 14. A mounting assembly 38 is pivotally secured at “P” to thedistal end of housing portion 36, and is configured to receive theproximal end of tool assembly 17 such that pivotal movement of toolassembly 17 about an axis at “P”, perpendicular to the longitudinal axisof housing portion 36, effects articulation of tool assembly 17.

With general reference to FIG. 2, loading unit 16 includes a mountingassembly 40. Mounting assembly 40 includes an upper and a lower mountingportion 40 a, 40 b, respectively. An axial drive assembly 50 isoperatively associated with and slidably disposed between cartridgeand/or anvil assembly 18, 20. With reference to FIG. 2, axial driveassembly 50 includes an elongated drive beam 52 having a distal end 54and a proximal end 56. Drive beam 52 may be constructed from a singlesheet of material or, preferably, multiple stacked sheets.

Proximal end 56 of drive beam 52 of drive assembly 50 includes a pair ofresilient engagement fingers that receive a pusher. The pusher isdimensioned and configured to mountingly engage a drive member, e.g., adrive rod or control rod (not shown) when the proximal end of loadingunit 16 is engaged with elongated body 14 of surgical stapling apparatus10. The control rod functions to impart axial movement of drive assembly50 from handle assembly 12.

Distal end 54 of drive beam 52 of drive assembly 50 includes a head 60with a laterally extending upper portion 64 a, a laterally extendinglower portion 64 b, and a central wall portion 62. A distal edge ofcentral wall portion 62 defines a knife blade or the like 66.

As seen in FIG. 2, anvil assembly 20 includes an anvil plate 70 having aplurality of staple deforming pockets/cavities (not shown) and a coverplate 72 secured to a top surface of anvil plate 70, having a cavity(not shown) is defined therebetween. The cavity defined between theanvil plate 70 and cover plate 72 is dimensioned to receive the upperportion 64 a of head 60 therein. A longitudinal slot 70 b extendsthrough anvil plate 70 to facilitate passage of central wall portion 62of head 60 therethrough. Additionally, cover plate 72 defines a pair ofopposed recesses 72 a formed therein which align with the proximal pairof recesses 70 d formed in anvil plate 70 when cover plate 72 isassembled with anvil plate 70.

With continued reference to FIG. 2, anvil plate 70 defines a proximalpair of recesses 70 d formed near a proximal end of anvil plate 70 anddisposed, one each, on opposed sides of longitudinal slot 70 b. Anvilplate 70 defines a distal pair of recesses 70 e formed near a distal endof anvil plate 70 and disposed, one each, on opposed sides oflongitudinal slot 70 b. In one embodiment, at least one of the recessesof each of the proximal pair of recesses 70 d and the distal pair ofrecesses 70 e is preferably non-circular and constricting, or has areduced width dimension, so as to frictionally engage and/or pinch ananchor “5”.

As used herein the term anchor is understood to include and is notlimited to sutures, threads, tethers, straps, bands, lines, wires,cables, fasteners, tacks or any other material suitable for the intendedpurpose disclosed herein. In certain embodiments, the anchor is anextension of the staple line reinforcement material discussed below. Theanchor may comprise an integral part of the staple line reinforcementmaterial, or may be formed from the same or a similar material andattached to the staple line reinforcement material.

As seen in FIGS. 2 and 2A, anvil assembly 20 further includes a surgicalanvil buttress “B1”, pledget or the like operatively secured to a lowersurface or tissue contacting surface of anvil plate 70, by an anchor“S”, to overlie at least some of anvil pockets 70 a and/or at least aportion of a length of longitudinal slot 70 b. In particular, an anchor“S” is cinched around a proximal portion of surgical anvil buttress “B1”and each of the proximal pair of recesses 70 d and an anchor “5” iscinched around a distal portion of the surgical anvil buttress “B1” andeach of the distal pair of recesses 70 e.

Surgical anvil buttress “B1” includes a proximal pair of notches formedin side edges aligned with the proximal pair of recesses 70 d of anvilplate 70, a distal pair of notches formed in side edges thereof alignedwith the distal pair of recesses 70 e of anvil plate 70, and a proximalnotch formed in a proximal edge thereof aligned with longitudinal slot70 b when surgical anvil buttress “B1” is secured to anvil assembly 20.Surgical anvil buttress “B1” further includes a tongue or tab extendingfrom a distal edge thereof to facilitate with the attachment of surgicalanvil buttress “B1” to anvil assembly 20 during the assembly process. Itis contemplated that the tongue is removed from surgical anvil buttress“B1” following securement of surgical anvil buttress “B1” to anvilassembly 20 and prior to packaging or shipment.

As seen in FIGS. 2-9, anvil assembly 20 further includes a releaseassembly 74 disposed between anvil plate 70 and cover plate 72 at alocation in operative registration with the distal pair of recesses 70e. Release assembly 74 includes a guide plate 75 defining an arcuateslot 75 a formed therethrough. Slot 75 a is configured and dimensionedto receive a tool (not shown) therethrough. The function and purpose ofslot 75 a will be discussed in greater detail below.

Release assembly 74 further includes a lock or anchor bar 76 pivotallyconnected to anvil plate 70 (as seen in FIGS. 4 and 5) and/or optionallycover plate 72 (shown in FIG. 2). Anchor bar 76 includes a body portion76 a defining an elongate channel or slot 76 b therein and a finger 76 cextending from an edge thereof. Finger 76 c is in operative registrationwith one of the distal pair of recesses 70 e, preferably, the one of thedistal pair of recesses having the relatively larger width dimension.

Suture release assembly 74 further includes an anchor bar actuationmember 77 pivotally connected to anvil plate 70 (as seen in FIGS. 4 and5) and/or optionally cover plate 72 (shown in FIG. 2). Actuation member77 includes an eccentric cam 77 a defining a central axis of rotationabout which actuation member is permitted to rotate. Actuation member 77includes a nub or boss 77 b extending from a surface of eccentric cam 77a in a direction substantially parallel to and offset a radial distancefrom the central axis of rotation of eccentric cam 77 a. Boss 77 b isslidably and rotatably disposed in elongate slot 76 b of anchor bar 76.Actuation member 77 further includes a release bar 77 c extendingsubstantially tangentially from eccentric cam 77 a from a sidesubstantially opposite to boss 77 b. Release bar 77 c defines a pin 77 dformed thereon which is in registration with the arcuate slot 75 a ofguide plate 75. In operation, as eccentric cam 77 a is rotated, pin 77 dof release bar 77 c follows along the path of arcuate slot 75 a of guideplate 75.

As seen in FIGS. 6 and 7, suture release assembly 74 includes a lockingor anchoring configuration wherein finger 76 c of anchor bar 76 extendsinto or overlies the respective one of the pair of distal recesses 70 ein operative registration therewith, release bar 77 c of actuationmember 77 extends across knife slot 70 b of anvil plate 70, and pin 77 dof release bar 77 c is disposed at or near a first end of arcuate slot75 a of guide plate 75. It is contemplated that suture release assembly74 may include a friction fit or snap fit feature for maintaining and/orretaining suture release assembly 74 in the locking or anchoringconfiguration at all times following the manufacturing/assembly processand prior to a complete firing of surgical stapling apparatus 10.

As seen in FIGS. 8 and 9, suture release assembly 74 includes an open orrelease configuration wherein finger 76 c of anchor bar 76 does notextend into or overlie the respective one of the pair of distal recesses70 e in operative registration therewith, release bar 77 c of actuationmember 77 does not extend across knife slot 70 b of anvil plate 70, andpin 77 d of release bar 77 c is disposed at or near a second end ofarcuate slot 75 a of guide plate 75.

Suture release assembly 74 is used by a manufacturer during the assemblyprocess of surgical stapling apparatus 10 to secure, with a surgicalsuture or tether, a surgical anvil buttress “B” to a tissue contactingsurface of the anvil plate 70, and by the end user of surgical staplingapparatus 10 to automatically release or free the surgical anvilbuttress “B” from the tissue contacting surface of the anvil plate 70upon a complete firing of the surgical stapling apparatus 10.

With reference to FIGS. 6-9, during the manufacturing process, withsuture release assembly 74 in the open or release configuration (FIGS. 8and 9), a surgical anvil buttress “B” is laid over the tissue contactingsurface of anvil plate 70. Then, a first end of a surgical suture “S1”is inserted into one of the pair of distal recesses 70 e and a secondend of surgical suture “S1” is extended across the surgical anvilbuttress “B1” (see FIG. 2) and inserted into the other of the pair ofdistal recesses 70 e. It is contemplated that the first end of surgicalsuture “S1” may include a knot, stop or the like (not shown) sized so asto not pass through the narrower recess of the distal pair of recesses70 e.

With the second end of the surgical suture “S1” disposed in the pair ofdistal recesses 70 e, and with the surgical suture “S1” pulled taughtacross the surgical anvil buttress “B”, a tool (not shown) is insertedthrough arcuate slot 75 a of guide plate 75 and engaged with an openingprovided in the pin 77 d of release bar 77 c. With reference to FIGS. 6and 7, the tool is then manipulated to move through or along arcuateslot 75 a of guide plate 75, thereby actuating or moving release bar 77c and rotating eccentric cam 77 a. As eccentric cam 77 a is rotated,boss 77 b is rotated around the pivot axis of eccentric cam 77 a andacts on the walls of elongate slot 76 b of anchor bar 76 thereby causinganchor bar 76 to pivot. As anchor bar 76 is pivoted, finger 76 c thereofis caused to extend into or overlies one of the distal recesses 70 e andto pinch the second end of the surgical suture disposed therewithin.Meanwhile, release bar 77 c has been moved to a position extendingacross knife slot 70 b of anvil plate 70. Suture release assembly 74 isnow in the locking or anchoring configuration, as described above. Thedistal recess 70 e that cooperates with the finger 76 c is desirablyrelatively wide so as to allow the suture “S1” to easily pass into andout of the recess 70 e when the 76 anchor bar is away from the recess 70e. The other distal recess 70 e, arranged on the opposite lateral sideof the anvil plate 70, may be the same size, or may be small enough tocinch the suture “S1” and hold the suture in place to facilitateassembly.

In operation, with surgical anvil buttress “B1” secured against thelower surface of anvil plate 70, during firing of surgical staplingapparatus 10, as drive assembly 50 is advanced (i.e., moved from aproximal-most position to a distal-most position), knife blade 66 slicesthrough a central section of the proximal suture “S2”, thereby freeingthe proximal end of the surgical anvil buttress “B1” from anvil assembly20. During use, as the firing stroke of surgical stapling apparatus 10is nearing completion and as drive assembly 50 approaches a distal endof knife slot 70 b of anvil plate 70, as seen in FIG. 9, drive assembly50 contacts release bar 77 c, urging release bar 77 c and, in turn,eccentric cam 77 a to rotate about the pivot axis thereof. As eccentriccam 77 a is rotated, boss 77 b is rotated around the pivot axis ofeccentric cam 77 a and acts on the walls of elongate slot 76 b of anchorbar 76 thereby causing anchor bar 76 to pivot. As anchor bar 76 ispivoted, finger 76 c thereof is caused to move away from the relativelywider distal recess 70 e and to release the second end of the surgicalsuture “S” disposed therewithin. With the second end of surgical suture“S” released or free, the distal end of the surgical anvil buttress “B1”is free to separate from the tissue contacting surface of anvil plate70.

As seen in FIGS. 1 and 2, cartridge assembly 18 includes a carrier 80defining an elongated support channel 80 a. Elongated support channel 80a of carrier 80 receives a staple cartridge 82 therein. Correspondingtabs and slots formed along staple cartridge 82 and carrier 80 functionto retain staple cartridge 82 within carrier 80. A pair of supportstruts formed on and extending from staple cartridge 82 are positionedto rest on side walls of carrier 80 to further stabilize staplecartridge 82 within support channel 80 a of carrier 80. Staple cartridge82 includes retention slots 82 a formed therein for receiving aplurality of fasteners 84 and pushers 86. A plurality of spaced apartlongitudinal slots 82 b extend through staple cartridge 82 toaccommodate upstanding cam wedges 90 a of an actuation sled 90. Theactuation sled 90 includes a central upstanding wedge or wall 90 b.Central wall 90 b defines a distal notch or shoulder 90 c formed therein(See FIG. 2).

A central longitudinal slot 82 c is formed in and extends along thelength of staple cartridge 82 to facilitate passage of central wallportion 62 of head 60 therethrough. During operation of surgical stapler10, actuation sled 90 translates through longitudinal slots 82 b ofstaple cartridge 82 to advance cam wedges 90 a into sequential contactwith pushers 92, to cause pushers 92 to translate vertically withinretention slots 82 a and urge fasteners 84 (e.g., staples) from slots 82a into the staple forming cavities 70 a of anvil plate 70 of anvilassembly 20.

With continued reference to FIGS. 1 and 2, staple cartridge 82 defines aproximal pair of recesses 82 e formed near a proximal end thereof anddisposed, one each, on opposed sides of longitudinal slot 82 c. Staplecartridge 82 further defines a distal pair of recesses 82 f formed neara distal end thereof and disposed, one each, on opposed sides oflongitudinal slot 82 c. In one embodiment, at least one of the recessesof each of the proximal pair of recesses 82 e and the distal pair ofrecesses 82 f is preferably non-circular and constricting or otherwisearranged so as to frictionally engage and/or pinch an anchor “S”.

As seen in FIGS. 1 and 2B, cartridge assembly 18 further includes asurgical cartridge buttress “B2”, pledget or the like operativelysecured to an upper surface or tissue contacting surface of staplecartridge 82, by anchors “S3” and “S4”, to overlie at least some ofstaple pockets 82 a and/or at least a portion of a length oflongitudinal slot 82 c. In particular, an anchor “S4” is cinched arounda proximal portion of surgical cartridge buttress “B2” and each of theproximal pair of recesses 82 e and an anchor “S3” is cinched around adistal portion of the surgical cartridge buttress “B2” and each of thedistal pair of recesses 82 f.

In one particular embodiment, a first end of each anchor “S” includes aknot, stop or the like (not shown) sized so as to not pass through onerecess of the proximal pair of recesses 82 e and a second end of eachanchor “S” passes over, and transversely across, surgical cartridgebuttress “B2”, at least once, and back through the other recess of theproximal pair of recesses 82 e. For example, the second end of eachanchor “S” may be pinched or cinched in the other recess of the proximalpair of recesses 82 e so as to anchor the second end of the anchor “S”and secure the surgical cartridge buttress “B2” against the tissuecontacting surface of staple cartridge 82. Similarly, an anchor “S3” isused to extend transversely across surgical cartridge buttress “B2” andinto engagement with the distal pair of recesses 82 f.

In a further embodiment, the release assembly is arranged to cut thesuture “S.” The arcuate slot 75 a on the guide plate 75 extends in theopposite direction so that it is arranged to drive the anchor bar 95toward the suture “S.” The surface of the anchor bar 76 that faces thesuture S includes a sharpened edge and cuts the suture when actuated bythe drive assembly.

Surgical cartridge buttress “B2” includes a proximal pair of notchesformed in side edges aligned with the proximal pair of recesses 82 e ofstaple cartridge 82, a distal pair of notches formed in side edgesthereof aligned with the distal pair of recesses 82 f of staplecartridge 82, and a proximal notch formed in a proximal edge thereofaligned with longitudinal slot 82 c when surgical cartridge buttress“B2” is secured to staple cartridge 82. Surgical cartridge buttress “B2”further includes a tongue or tab extending from a distal edge thereof tofacilitate with the attachment of surgical cartridge buttress “B2” tostaple cartridge 82 during the assembly process. It is contemplated thata width of surgical cartridge buttress “B2” may be reduced in a proximalportion thereof. It is further contemplated that the tongue is removedfrom surgical cartridge buttress “B2” following securement of surgicalcartridge buttress “B2” to staple cartridge 82 and prior to packaging orshipment.

As seen in FIGS. 2 and 10-14, cartridge assembly 18 further includes acartridge release assembly 94 supported in and near a distal end ofstaple cartridge 82. Release assembly 94 includes a lock or anchor bar95 pivotally connected to staple cartridge 82. Anchor bar 95 includes abody portion 95 a having a finger 95 b extending from an edge thereof.Finger 95 b is in operative registration with one of the distal pair ofrecesses 82 f, preferably, the one of the distal pair of recesses havingthe relatively larger width dimension.

Release assembly 94 further includes an anchor bar actuation member 97pivotally connected to anchor bar 95 (as seen in FIGS. 11 and 12).Actuation member 97 includes a first cam surface 97 a located along aproximal edge of actuation member 97 and extending across centrallongitudinal slot 82 c of staple cartridge 82, and a second eccentriccam surface 97 b extending distally and laterally from actuation member97 in close proximity to the one of the distal pair of recesses 82 fthat is operatively associated with finger 95 b of anchor bar 95. Firstcam surface 97 a of actuation member 97 is substantially arcuate orconvex. Actuation member 97 defines an aperture or opening 97 cconfigured and dimensioned to receive a pin 95 c of anchor bar 95therein so as to anchor bar 95 and actuation member 97 to pivot orrotate relative to one another.

In operation, rotation of actuation member 97 in a first direction,about its pivot point, results in second cam surface 97 b pressingagainst a surface 82 g (see FIGS. 13 and 14) of staple cartridge 82 andthus moving finger 95 b at least partially over and/or across the one ofthe distal pair of recesses 82 f associated therewith.

As seen in FIG. 13, suture release assembly 94 includes a locking oranchoring configuration wherein first cam surface 97 a of actuationmember 97 extends into and across central longitudinal slot 82 c ofstaple cartridge 82, wherein second cam surface 97 b of actuation member97 is pressed against surface 82 g of staple cartridge 82, and thusfinger 95 b of anchor bar 95 extends into or overlies the respective oneof the pair of distal recesses 82 f in operative registration therewith.Fastener release assembly 94 may be maintained in the locking oranchoring configuration by way of a biasing member or a detent thatengages actuation member 97 in a manner so as to keep actuation member97 in the locked or anchoring configuration. When in such a locked oranchoring configuration, the suture “S3” may be urged into recess 82 fof staple cartridge 82. It is contemplated that suture release assembly94 may include a friction fit or snap fit feature for maintaining and/orretaining suture release assembly 94 in the locking or anchoringconfiguration at all times following the manufacturing/assembly processand prior to a complete firing of surgical stapling apparatus 10.

As seen in FIGS. 12 and 14, suture release assembly 94 includes an openor release configuration wherein finger 95 b of anchor bar 95 does notextend into or overlie the respective one of the pair of distal recesses82 f in operative registration therewith, first cam surface 97 a ofactuation member 97 does not extend into and across central longitudinalslot 82 c of staple cartridge 82, and second cam surface 97 b ofactuation member 97 is not pressed against surface 82 g of staplecartridge 82.

Suture release assembly 94 is used by a manufacturer during the assemblyprocess of surgical stapling apparatus 10 to secure, with an anchor,surgical suture, or tether “S”, a surgical cartridge buttress “B2” (seeFIG. 2) to a tissue contacting surface of the staple cartridge 82, andby the end user of surgical stapling apparatus 10 to automaticallyrelease or free the surgical cartridge buttress “B2” from the tissuecontacting surface of the staple cartridge 82 upon a complete firing ofthe surgical stapling apparatus 10.

With reference to FIGS. 10-14, during the manufacturing process, withsuture release assembly 94 in the open or release configuration, asurgical cartridge buttress “B2” is laid over the tissue contactingsurface of staple cartridge 82. Then, a first end of a surgical suture“S” is inserted into the relatively narrower of the pair of distalrecesses 82 f and a second end of surgical suture “S” is extended acrossthe surgical cartridge buttress “B2” and inserted into the relativelywider of the pair of distal recesses 82 f. It is contemplated that thefirst end of surgical suture “S” may include a knot, stop or the like(not shown) sized so as to not pass through the narrower recess of thedistal pair of recesses 82 f.

As seen in FIG. 11, staple cartridge 82 includes an access opening 83formed therein which is used to insert and receive suture releaseassembly 94 therein and to provide access to actuation member 97. Withthe second end of the surgical suture “S” disposed in the relativelywider of the pair of distal recesses 82 f, and with the surgical suture“S” pulled taught across the surgical cartridge buttress “B2,” actuationmember 97 is rotated about the pivot axis causing first cam surface 97 aof actuation member 97 to extend into and across central longitudinalslot 82 c of staple cartridge 82 and causing second cam surface 97 b ofactuation member 97 to press against surface 82 g (see FIGS. 13 and 14)of staple cartridge 82. In so doing, anchor bar 95 is pivoted by anamount sufficient for finger 95 b of anchor bar 95 to extend into oroverlies the respective one of the pair of distal recesses 82 f inoperative registration therewith thereby pinch the second end of thesurgical suture disposed therewithin. Suture release assembly 94 is nowin the locking or anchoring configuration, as described above.

In operation, with surgical cartridge buttress “B1” secured against thetissue contacting surface of staple cartridge 82, during firing ofsurgical stapling apparatus 10, as drive assembly 50 is advanced (i.e.,moved from a proximal-most position to a distal-most position), knifeblade 66 slices through a central section of the proximal suture “S4”,thereby freeing the proximal end of the surgical cartridge buttress “B2”from staple cartridge 82. During use, as the firing stroke of surgicalstapling apparatus 10 is nearing completion and as drive assembly 50approaches a distal end of central longitudinal slot 82 c of staplecartridge 82, as seen in FIG. 14, drive assembly 50 contacts first camsurface 97 a of actuation member 97, urging actuation member 97 torotate. Second cam surface 97 b of actuation member 97 also rotatesabout the pivot axis of pivot pin 95 c thereof. As eccentric second camsurface 97 b is rotated about the pivot axis second cam surface 97 b,the distance between the pivot pin 95 c and the surface 82 g of staplecartridge 82 is reduced thereby pivoting anchor bar 95 about pivot pin95 c. As anchor bar 95 is pivoted, finger 95 c thereof is caused to moveaway from the relatively wider distal recess 82 f and to release thesecond end of the surgical suture “S” disposed therewithin. With thesecond end of surgical suture “S” released or free, the distal end ofthe surgical cartridge buttress “B2” is free to separate from the tissuecontacting surface of staple cartridge 82. The distal recesses 82 f thatis in operative registration with finger 95 b of anchor bar 95 isdimensioned so that, notwithstanding the rotation of anchor bar 95, thesuture “S3” is not cinched therewithin.

As drive assembly 50 is advanced from the proximal position to thedistal position, knife blade 66 thereof slices or cuts longitudinallythrough both surgical anvil buttress “B1” and surgical cartridgebuttress “B2”, thereby dividing the buttresses “B1, B2” substantially inhalf. Additionally, as drive assembly 50 is advanced from aproximal-most position to a distal-most position, upstanding cam wedges90 a of actuation sled 90 actuates pushers 92, to cause pushers 92 totranslate vertically within retention slots 82 a and urge fasteners 84from slots 82 a. As fasteners 84 (e.g., staples) are urged from slots 82a of staple cartridge 82, legs of fasteners 84 penetrate and passthrough both surgical anvil buttress “B1” and surgical cartridgebuttress “B2”, through any tissue (not shown) interposed betweensurgical anvil buttress “B1” and surgical cartridge buttress “B2”, andare formed against or within staple forming cavities 70 a of anvil plate70 of anvil assembly 20. Buttresses “B1, B2” preferably includeperforations that divide the buttresses and facilitate removal of theapparatus from the tissue.

According to the present disclosure, surgical anvil buttress “B1” and/orsurgical cartridge buttress “B2” is pre-loaded (i.e., from themanufacturer) onto anvil assembly 20 or cartridge assembly 18,respectively, of the loading unit 16. After the loading unit is fired,an additional unfired loading unit, with or without buttresses “B”, canbe loaded onto the surgical apparatus. In certain embodiments, thereplaceable loading unit is a removable cartridge that can be insertedinto support channel of carrier 80. A buttress and release assembly maybe pre-loaded onto the removable cartridge and means for the user of thesurgical apparatus to load a buttress onto the anvil assembly can beprovided. For example, a buttress having an adhesive can be used.Additional or replacement buttresses “B” for anvil assembly 20 and/orcartridge assembly 18 may be secured to either anvil assembly 20 orcartridge assembly 18 as needed or desired.

In a further embodiment, the release assembly may be arranged to cut thesuture “S.” The cam surface 97 b on the actuation member 97 may bearranged to cam the anchor bar 95 toward the suture “S.” The surface ofthe anchor bar 97 that faces the suture “S” may include a sharpened edgeand may cut the suture when actuated by the drive assembly.

Turning now to FIGS. 15-25, a loading unit according to anotherembodiment of the present disclosure, for surgical stapling apparatus10, is generally designated as 116. Loading unit 116 is substantiallysimilar to loading unit 16 and will only be discussed in detail hereinto the extent necessary to identify differences in construction andoperation.

As seen in FIGS. 15-20, anvil assembly 120 of loading unit 116 includesa suture release assembly 174 disposed between anvil plate 170 and coverplate 172 at a location in operative registration with the distal pairof recesses 170 e. Suture release assembly 174 includes a link arm 175pivotally connected to anvil plate 170 (as seen in FIG. 18) and/oroptionally cover plate 172. Link arm 175 includes a body portion 175 adefining a pocket or recess 175 c formed in a first side edge 175 bthereof and a camming surface 175 d defined substantially along anadjacent side or proximal edge thereof. Pocket 175 c has a substantiallyarcuate, circular or rounded profile. As seen in FIGS. 18 and 20, linkarm 175 includes a pivot pin 175 e extending from body portion 175 a forpivotally connecting link arm 175 to anvil assembly 120.

Release assembly 174 further includes a pusher bar 177 pivotallyconnected to link arm 175 and slidably disposed between anvil plate 170and cover plate 172. Pusher bar 177 includes a body portion 177 a havinga substantially rectangular configuration and a head 177 b, extendingfrom a corner of body portion 177 a, and having a substantially circularor rounded configuration. Head 177 b of pusher bar 177 is configured anddimensioned for pivotable and/or rotatable connection in pocket 175 c oflink arm 175.

As seen in FIG. 19, suture release assembly 174 includes an unactuatedconfiguration wherein pusher bar 177 does not extend into or overlie therespective one of the pair of distal recesses 170 e in operativeregistration therewith, and a longitudinal axis of link arm 175 isoriented substantially parallel with a longitudinal axis of loading unit116. It is contemplated that suture release assembly 174 may include afriction fit or snap fit feature for maintaining and/or retaining suturerelease assembly 174 in the locking or anchoring configuration at alltimes following the manufacturing/assembly process and prior to acomplete firing of the surgical stapling apparatus.

As seen in FIG. 20, suture release assembly 174 includes an actuatedconfiguration wherein pusher bar 177 extends into or overlies therespective one of the pair of distal recesses 170 e in operativeregistration therewith, and a longitudinal axis of link arm 175 isoriented substantially transverse to the longitudinal axis of loadingunit 116.

With reference to FIGS. 15-20, during the manufacturing process, withsuture release assembly 174 in the unactuated configuration, a surgicalanvil buttress (not shown) is laid over the tissue contacting surface ofanvil plate 170. Then, a first end of a surgical suture “S1” is insertedinto one of the pair of distal recesses 170 e and a second end ofsurgical suture “S1” is extended across the surgical anvil buttress (notshown) and inserted into the other of the pair of distal recesses 170 e.It is contemplated that each of the pair of distal recesses 170 e is anopen ended constricting slot so as to frictionally grip or cinch asurgical suture “S1” disposed therein.

In operation, with a surgical anvil buttress (not shown) secured againstthe lower surface of anvil plate 170, during firing of the surgicalstapling apparatus, as drive assembly 150 is advanced (i.e., moved froma proximal-most position to a distal-most position), knife blade 166slices through a central section of the proximal suture (not shown),thereby freeing the proximal end of the surgical anvil buttress (notshown) from anvil assembly 120. During use, as the firing stroke of thesurgical stapling apparatus is nearing completion and as drive assembly150 approaches a distal-most end of knife slot 170 b of anvil plate 170,as seen in FIG. 20, drive assembly 150 contacts camming surface 175 d oflink arm 175, thus urging link arm 175 to rotate or pivot around thepivot pin and, in turn, urging pusher bar 177 to translate in thedirection of the slot. As pusher bar 177 is translated, pusher bar 177comes into contact with and urges the second end of suture “S1” out ofthe distal recess 170 e that is registration therewith to release thesecond end of suture “S1” therefrom. With the second end of surgicalsuture “S1” released or free from distal recess 170 e, the distal end ofthe surgical anvil buttress “B1” is free to separate from the tissuecontacting surface of anvil plate 170.

As seen in FIGS. 15, 16 and 21-25, cartridge assembly 118 of loadingunit 116 includes a cartridge release assembly 194 supported in and neara distal end of staple cartridge 182. Release assembly 194 includes aretainer 195 supported in a distal end of staple cartridge 182 at alocation near a distal end of longitudinal slot 182 c and at leastpartially extending thereacross. Retainer 195 includes a body portion195 a, a boss 195 b extending from a surface thereof, and defines achannel or recess 195 c formed in a surface thereof and extendingthrough a side thereof. When supported in staple cartridge 182, recess195 c of retainer 195 is in registration with one of the pair of distalrecesses 182 f of staple cartridge 182.

Release assembly 194 further includes a pusher member 196 having a headportion 196 a pivotally connected to boss 195 b of retainer 195. Pushermember 196 further includes a first leg member 196 b extending from headportion 196 a and a second leg member 196 c connected to a free end offirst leg member 196 b via a living hinge connection 196 d. Pushermember 196 further includes piston 196 e connected to a free end ofsecond leg member 196 c via a living hinge connection 196 f. Piston 196e is slidably disposed and translatable within recess 195 c of retainer195. In certain other embodiments, the pusher is a linkage assemblyhaving a first link pivotably connected to the cartridge at one end. Theother end of the first link is pivotably connected to a first end of asecond link. The opposite, second, end of the second link is confined inthe recess of the retainer.

As seen in FIG. 24, release assembly 194 includes an unactuatedconfiguration wherein piston 196 e does not extend into or overlie therespective one of the pair of distal recesses 182 f, and first legmember 196 b and second leg member 196 c are angled with respect to oneanother and project proximally along longitudinal slot 182 c of staplecartridge 182. It is contemplated that suture release assembly 194 mayinclude a friction fit or snap fit feature for maintaining and/orretaining suture release assembly 194 in the locking or anchoringconfiguration at all times following the manufacturing/assembly processand prior to a complete firing of the surgical stapling apparatus.

As seen in FIG. 25, suture release assembly 194 includes an actuatedconfiguration wherein piston 196 e extends into or overlies therespective one of the pair of distal recesses 182 f in operativeregistration therewith, and first leg member 196 b and second leg member196 c are extended substantially along a common axis.

With reference to FIGS. 21-25, during the manufacturing process, withsuture release assembly 194 in the unactuated configuration, a surgicalcartridge buttress (not shown) is laid over the tissue contactingsurface of staple cartridge 182. Then, a first end of a surgical suture“S3” is inserted into one of the pair of distal recesses 182 f and asecond end of surgical suture “S3” is extended across the surgicalcartridge buttress and inserted into the other of the pair of distalrecesses 182 f. It is contemplated that at least the recess 182 f thatis adjacent the retainer 195 is an open ended constricting slot so as tofrictionally grip or cinch a surgical suture “S3” disposed therein.

In operation, with surgical cartridge buttress (not shown) securedagainst the tissue contacting surface of staple cartridge 182, duringfiring of surgical stapling apparatus 10, as drive assembly 150 isadvanced (i.e., moved from a proximal-most position to a distal-mostposition), knife blade 166 slices through a central section of aproximal suture (not shown), thereby freeing the proximal end of thesurgical cartridge buttress from staple cartridge 182. During use, asthe firing stroke of surgical stapling apparatus 10 is nearingcompletion and as drive assembly 150 approaches a distal end of centrallongitudinal slot 182 c of staple cartridge 182, as seen in FIG. 25,drive assembly 150 contacts living hinge connection 196 d between firstleg member 196 b and second leg member 196 c. As drive assembly 150 isfurther advanced distally, drive assembly 150 presses against livinghinge connection 196 d, causing first leg member 196 b and second legmember 196 c to extend. As first leg member 196 b and second leg member196 c extend, piston 196 e is translated through recess 195 c ofretainer 195. As piston 196 e is translated through recess 195 c ofretainer 195, piston 196 e engages the second end of suture “S3” andurges suture “S3” out of the distal recess 182 f that is registrationtherewith to release the second end of suture “S3” therefrom. With thesecond end of surgical suture “S3” released or free from distal recess182 f, the distal end of the surgical cartridge buttress “B” is free toseparate from the tissue contacting surface of staple cartridge 182.

Turning now to FIGS. 26-29, a loading unit according to anotherembodiment of the present disclosure, for surgical stapling apparatus10, is generally designated as 216. Loading unit 216 is substantiallysimilar to loading unit 16 or 116 and will only be discussed in detailherein to the extent necessary to identify differences in constructionand operation.

As seen in FIGS. 26-29, anvil assembly 220 of loading unit 216 includesa release assembly 274 disposed between anvil plate 270 and cover plate272 at a location in operative registration with the distal pair ofrecesses 270 e. Release assembly 274 includes a cam 275 pivotallyconnected to anvil plate 270 and/or cover plate 272. Cam 275 includes abody portion 275 a having an ovular profile and defining a cam surface275 b that is in operative association with one of the distal pair ofrecesses 270 e. Cam 275 further includes a finger or stem 275 cprojecting at an angle from a lateral edge of body portion 275 a.

Release assembly 274 further includes a pusher 277 slidably disposedbetween anvil plate 270 and cover plate 272. As seen in FIGS. 27-29,pusher 277 may be slidably disposed within longitudinal slot 270 b ofanvil plate 270 a. Pusher 277 includes a cam arm 277 a extendingsubstantially in a distal direction. Cam arm 277 a is configured anddimensioned to engage and/or act on finger 275 c extending from cam 275.

As seen in FIG. 28, suture release assembly 274 includes an unactuatedconfiguration wherein body portion 275 a of cam 275 does not extend intoor overlie the respective one of the pair of distal recesses 270 e inoperative registration therewith, and pusher 277 is in a retracted ornon-advanced position. As seen in FIG. 28, cam arm 277 a of pusher 277is adjacent finger 275 c and may, although not necessarily, be incontact with finger 275 c of cam 275.

As seen in FIG. 29, suture release assembly 274 includes an actuatedconfiguration wherein body portion 275 a of cam 275 extends into oroverlies the respective one of the pair of distal recesses 270 e inoperative registration therewith, and pusher 277 is in an advancedposition. As seen in FIG. 29, when pusher 277 is in the advancedposition, cam arm 277 a of pusher 277 has engaged finger 275 c of cam275 to rotate body portion 275 a of cam 275.

In operation, with an surgical anvil buttress (not shown) securedagainst the lower surface of anvil plate 270, during firing of thesurgical stapling apparatus, as drive assembly 250 approaches adistal-most end of knife slot 270 b of anvil plate 270, drive assembly250 contacts pusher 277, thus driving pusher 277 distally. As pusher 277is driven distally, as seen in FIGS. 28 and 29, cam arm 277 a of pusher277 engages finger 275 c of cam 275 to rotate or pivot cam 275. As cam275 is rotated, cam surface 275 b of cam 275 comes into contact with andurges the second end of suture “S1” out of the distal recess 270 e thatis registration therewith to release the second end of suture “S1”therefrom. With the second end of surgical suture “S1” released or freefrom distal recess 270 e, the distal end of the surgical anvil buttressis free to separate from the tissue contacting surface of anvil plate270.

Turning now to FIGS. 30 and 31, a loading unit according to anotherembodiment of the present disclosure, for surgical stapling apparatus10, is generally designated as 316. Loading unit 316 is substantiallysimilar to loading unit 16, 116 or 216 and will only be discussed indetail herein to the extent necessary to identify differences inconstruction and operation.

As seen in FIGS. 30 and 31, anvil assembly 320 of loading unit 316includes a release assembly 374 disposed between anvil plate 370 and thecover plate at a location in operative registration with the distal pairof recesses 370 e. Release assembly 374 includes a body portion 374 aslidably disposed within longitudinal slot 370 b of anvil plate 370 a.Release assembly 374 further includes a head portion 374 b connected toor extending from a distal surface of body portion 374 a. Head portion374 b defines a cam surface 374 c along a side edge thereof that isconfigured and dimensioned for operatively association with one of thedistal pair of recesses 370 e formed in anvil plate 370 a. Cam surface374 c may have an arcuate, curved or sinusoidal profile.

As seen in FIG. 30, suture release assembly 374 includes an unactuatedconfiguration wherein body portion 374 a is retracted and cam surface374 c does not extend into or across the respective one of the pair ofdistal recesses 370 e in operative registration therewith.

As seen in FIG. 31, suture release assembly 374 includes an actuatedconfiguration wherein body portion 374 a is advanced distally and camsurface 374 c extends into or overlies the respective one of the pair ofdistal recesses 370 e in operative registration therewith.

In operation, with a surgical anvil buttress (not shown) secured againstthe lower surface of anvil plate 370, during firing of the surgicalstapling apparatus, as drive assembly 350 approaches a distal-most endof knife slot 370 b of anvil plate 370, as seen in FIGS. 30 and 31,drive assembly 350 contacts body portion 374 a of release assembly 374,thus driving head portion 374 b distally. As head portion 374 b isdriven distally, cam surface 374 c comes into contact with and urges thesecond end of suture “S1” out of the distal recess 370 e that isregistration therewith to release the second end of suture “S1”therefrom. With the second end of surgical suture “S10” released or freefrom distal recess 370 e, the distal end of the surgical anvil buttressis free to separate from the tissue contacting surface of anvil plate370.

In a further embodiment, the driving head portion may include asharpened edge instead of cam surface 374 c. As the driving head portionis moved distally, the suture “S1” is caught between the sharpened edgeof the driving head portion and the side of the distal recess 370 e,severing the suture “S1.”

Turning now to FIGS. 32-38, a loading unit according to anotherembodiment of the present disclosure, for surgical stapling apparatus10, is generally designated as 416. Loading unit 416 is substantiallysimilar to loading unit 16, 116, 216 or 316 and will only be discussedin detail herein to the extent necessary to identify differences inconstruction and operation.

As seen in FIGS. 32-38, cartridge assembly 418 of loading unit 416includes a cartridge release assembly 494 supported in and near a distalend of staple cartridge 482. Release assembly 494 includes a retainer495 supported in a distal end of staple cartridge 482 at a location neara distal end of longitudinal slot 482 c and at least partially extendingthereacross. Retainer 495 includes a body portion 495 a, a boss 495 bextending from a surface thereof, and defines a channel or recess 495 cformed in a surface thereof and extending through a side thereof. Bodyportion 495 a of retainer 495 defines a slot 495 d formed in opposedsides thereof and which are configured to receive a suture therein. Whensupported in staple cartridge 482, recess 495 c of retainer 495 is inregistration with one of the pair of distal recesses 482 f of staplecartridge 482, and slots 495 d of retainer 495 are in registration withthe pair of distal recesses 482 f of staple cartridge 482 (see FIG. 32).

Release assembly 494 further includes a cam member 496 having a headportion 496 a pivotally connected to boss 495 b of retainer 495. Cammember 496 further includes a body portion 496 b extending from headportion 496 a. Body portion 496 b defines a first cam surface 496 c anda second cam surface 496 d each extending substantially tangentially toan axis of rotation of cam member 496.

Release assembly 494 further includes a sled 497 slidably disposedwithin channel 495 c of retainer 495. Sled 497 includes a body portion497 a defining a cam surface 497 b oriented to operatively engage secondcam surface 496 d of cam member 496, and a side wall 497 c inregistration with the one of the pair of distal recesses 482 f of staplecartridge 482 that is in registration with recess 495 c of retainer 495.

As seen in FIG. 37, release assembly 494 includes an unactuatedconfiguration wherein first cam surface 496 c of cam member 496 extendsacross longitudinal slot 482 c staple cartridge 482, side wall 497 c ofsled 497 does not extend into or over the one of the pair of distalrecesses 482 f of staple cartridge 482 that is in registrationtherewith, and second cam surface 496 d of cam member 496 issubstantially in flush contact with cam surface 497 b of sled 497.

As seen in FIG. 38, release assembly 494 includes an actuatedconfiguration wherein first cam surface 496 c of cam member 496 does notsubstantially extend across longitudinal slot 482 c of staple cartridge482, side wall 497 c of sled 497 extends into or over the one of thepair of distal recesses 482 f of staple cartridge 482 that is inregistration therewith, and second cam surface 496 d of cam member 496is spaced away from cam surface 497 b of sled 497.

With reference to FIGS. 32-38, during the manufacturing process, withsuture release assembly 494 in the unactuated configuration, a surgicalcartridge buttress (not shown) is laid over the tissue contactingsurface of staple cartridge 482. Then, a first end of a surgical suture“S3” is inserted into one of the pair of distal recesses 482 f and asecond end of surgical suture “S3” is extended across the surgicalcartridge buttress and inserted into the other of the pair of distalrecesses 482 f. It is contemplated that at least the distal recesses 482f adjacent the side wall 497 c is an open ended constricting slot so asto frictionally grip or cinch a surgical suture “S3” disposed therein.

In operation, with a surgical cartridge buttress (not shown) securedagainst the tissue contacting surface of staple cartridge 482, duringfiring of the surgical stapling apparatus, as drive assembly 450approaches a distal end of central longitudinal slot 482 c of staplecartridge 482, as seen in FIG. 38, drive assembly 450 contacts secondcam surface 496 c of cam member 496 extending across longitudinal slot482 c of staple cartridge 482.

As drive assembly 450 is further advanced distally, drive assembly 450presses against first cam surface 496 c of cam member 496, causing cammember 496 to rotate. As cam member 496 is rotated, second cam surface496 d thereof contacts and presses against cam surface 497 b of sled 497thus causing sled 497 to translate in recess 495 c of retainer 495. Assled 497 is translated through recess 495 c, side wall 497 c of sled 497engages the second end of suture “S3” and urges suture “S3” out of thedistal recess 482 f that is registration therewith to release the secondend of suture “S3” therefrom. With the second end of surgical suture“S3” released or free from distal recess 482 f, the distal end of thesurgical cartridge buttress is free to separate from the tissuecontacting surface of staple cartridge 482.

Turning now to FIGS. 39-46, an anvil assembly according to anotherembodiment of the present disclosure, for use with loading unit 116 (seeFIGS. 15-25), is generally designated as 520. Anvil assembly 520 issubstantially similar to anvil assembly 120 and will only be discussedin detail herein to the extent necessary to identify differences inconstruction and operation.

As seen in FIGS. 39 and 40, anvil assembly 520 includes a suture releaseassembly 574 disposed between anvil plate 570 and cover plate 572 at alocation in operative registration with the distal pair of recesses 570e of anvil plate 570. Suture release assembly 574 includes a link arm575 pivotally connected to anvil plate 570. Link arm 575 includes a bodyportion 575 a defining a pocket or recess 575 c formed in a first sideedge 575 b thereof and a camming surface 575 d defined substantiallyalong an adjacent side or proximal edge thereof. Pocket 575 c has asubstantially circular profile and defines an arcuate relief 575 e is aside wall thereof.

Release assembly 574 further includes a pusher bar 577 pivotallyconnected to link arm 575 and slidably disposed between anvil plate 570and cover plate 572. Pusher bar 577 includes a body portion 577 a havinga substantially rectangular configuration and a head 577 b, extendingfrom a corner of body portion 577 a, and having a substantially circularor rounded configuration. Body portion 577 a of pusher bar 577 definesan arcuate distal surface or wall 577 c configured to ride against asurface 570 f of anvil plate 570. Head 577 b of pusher bar 577 isconfigured and dimensioned for pivotable and/or rotatable connection inpocket 575 c of link arm 575. Head 577 b of pusher bar 577 includes astop member 577 d projecting from a side edge thereof and into arcuaterelief 575 e of pocket 575 c of link arm 575. A relative distance ofrotation of pusher bar 577 relative to link arm 575 is determined by arelative length of arcuate relief 575 e and a relative width of stopmember 577 d.

Turning now to FIGS. 41-46, in accordance with the present embodiment,anvil assembly 520 defines a proximal pair of recesses 570 d formed neara proximal end of anvil plate 570 and disposed, one each, on opposedsides of longitudinal slot 570 b. Anvil plate 570 defines a distal pairof recesses 570 e formed near a distal end of anvil plate 570 anddisposed, one each, on opposed sides of longitudinal slot 570 b. In oneembodiment, at least one of the recesses of each of the proximal pair ofrecesses 570 d and at least one of the recesses of the distal pair ofrecesses 570 e is in the form of a keyhole-shaped slot/recess.

In particular, as seen in FIG. 44, at least one of the recesses of eachof the proximal pair of recesses 570 d defines a uniform width centralportion 570 d ₁, an expanding or widening mouth portion 570 d ₂ disposedat one end of central portion 570 d ₁ and opening out beyond a side edgeof anvil plate 570, and an enlarged head portion 570 d ₃ disposed at anopposite end of central portion 570 d ₃. Central portion 570 d ₁ ofrecess 570 d defines a first width W1, and enlarged head portion 570 d ₃defines a second width W2 that is larger than first width W1.

As seen in FIG. 43, at least one of the recesses of each of the distalpair of recesses 570 e defines a uniform width central portion 570 e ₁,an expanding or widening mouth portion 570 e ₂ disposed at one end ofcentral portion 570 e ₁ and opening out beyond a side edge of anvilplate 570, and an enlarged head portion 570 e ₃ disposed at an oppositeend of central portion 570 e ₃. Central portion 570 e ₁ of recess 570 edefines a first width W1, and enlarged head portion 570 e ₃ defines asecond width W2 that is larger than first width W1. As seen in FIGS. 43and 44, enlarged head portion 570 e ₃ is oval in shape having a lengththat is greater than second width W2.

In this manner, the sutures will reside in the enlarged head portions ofthe proximal pair of recesses 570 d and the distal pair of recesses 570e, and the reduced width portions thereof will inhibit the sutures formsliding/walking out of the recesses without application of an externalforce thereto. By way of example, it is envisioned that width W1 isabout 0.009-0.011 inches, width W2 is about 0.014-0.016 inches, and thesutures have a diameter of about 0.0165-0.0185 inches.

Turning now to FIGS. 45 and 46, in accordance with the presentembodiment, anvil assembly 520 defines a distal pair of recesses 572 bformed near a distal end of cover plate 572 and disposed in operativeregistration with the distal pair of recesses 570 e of anvil plate 570.In one embodiment, at least one of the recesses of each of the distalpair of recesses 572 b of cover plate 572 is in the form of akeyhole-shaped slot/recess.

As seen in FIG. 46, at least one of the recesses of each of the distalpair of recesses 572 b defines a uniform width central portion 572 b ₁,an expanding or widening mouth portion 572 b ₂ disposed at one end ofcentral portion 572 b ₁ and opening out beyond a side edge of coverplate 572, and an enlarged head portion 572 b ₃ disposed at an oppositeend of central portion 572 b ₁. Central portion 572 b ₁ of recess 572 bdefines a first width W1, and enlarged head portion 572 b ₃ defines asecond width W2 that is larger than first width W1.

Keyhole-shaped slots or recesses 570 d, 570 e, 572 b facilitate theinsertion and/or release of a suture “S” (not shown) therefrom, ascompared to recesses 70 d, 70 e of anvil plate 70 and recess 72 b ofcover plate 72, as described above.

It is further contemplated that a keyhole-shaped slot or recess may beprovided in place of any of the side slots defined in any of the anvilassemblies and/or cartridge assemblies disclosed herein.

In further embodiments, recesses 570 d, 570 e, 572 b are provided withdifferently-shaped slots and configurations to facilitate the insertionand/or release of a suture “S” (not shown) in a variety ofcircumstances. While the following embodiments illustrate a recess onthe distal end of cover plate 572, it is contemplated that theseconfigurations may be applied equally to recesses on the anvil plate570.

Referring now to FIG. 47, a recess 572 f is shown having a uniform widthcentral portion 572 f ₁, an expanding or widening mouth portion 572 f ₂disposed at one end of central portion 572 f ₁ and opening out beyond aside edge of cover plate 572, and a circular head portion 572 f ₃disposed at an opposite end of central portion 572 f ₁. Central portion572 f ₁ of recess 572 f defines a first width W1 _(f), and circular headportion 572 f ₃ defines a second width W2 _(f) that is larger than firstwidth W1 _(f). Recess 572 f differs from recess 572 b in that theenlarged head portion 572 b ₃ is elongated or oval while the headportion 572 f ₃ is substantially circular.

Turning now to FIG. 48, a recess 572 g is shown having a uniform widthcentral portion 572 g ₁ disposed at an angle with a side edge of coverplate 572, an expanding or widening mouth portion 572 g ₂ disposed atone end of central portion 572 g ₁ and opening out beyond a side edge ofcover plate 572 and a rounded head portion 572 g ₃ disposed at anopposite end of central portion 572 g ₁. Recess 572 g is configured toengage a suture “S” (not shown) at an angle rather than substantiallytransverse to a side edge of cover plate 572 as in previous embodiments.Recess 572 g prevents a suture “S” (not shown) from sliding out ofrecess 572 g in a path substantially transverse to a side edge of coverplate 572. This may be particularly beneficial during the operation ofsurgical stapling apparatus 10, as the anvil assembly 520 is advancedthrough tissue.

Referring to FIG. 49, an embodiment of a recess 572 h is shown having auniform width central portion 572 h ₁, an expanding or widening mouthportion 572 h ₂ disposed at one end of central portion 572 h ₁ andopening out beyond a side edge of cover plate 572, and an enlarged headportion 572 h ₃ disposed at an opposite end of central portion 572 h ₁.Central portion 572 h ₁ of recess 572 h defines a first width W1 _(h),and enlarged head portion 572 h ₃ defines a second width W2 h that islarger than first width W1 _(h). Disposed within central portion 572 h ₁are a plurality of barbs 572 h ₁a such that upon insertion of a suture“S” (not shown) into a recess 572 h, the edges of 572 h _(1b) engagesuture “S” (not shown) so that it is restricted from motion away fromthe enlarged head portion 572 h ₃.

Turning to FIG. 50, disposed on an inner wall of the recess 572 h withinthe elongated head portion 572 h ₃ are a pair of steppes 572 h _(3a,3b).Steppes 572 h _(3a,b) are defined by ledges that are offset along a lineextending through the elongated head portion 572 h ₃. In otherembodiments, varying numbers of steppes may be present.

In use, the pair of steppes 572 h _(3a,3b) serve to trap suture “S” (notshown) within elongated head portion 572 h ₃ to prevent/inhibit distalmotion of the suture “S” (not shown) or withdrawal of suture “S” fromrecess 572 h. Suture “S” (not shown) is trapped along a path defined bythe internal wall of recess 572 h and steppes 572 h _(3a,3b). If suture“S” (not shown) is provided with barbs on its outer surface, steppes 572h _(3a,3b) may serve to engage the barbs on suture “S” (not shown) tofurther inhibit motion of sutures “S”. Thus, steppes 572 h _(3a,3b) workin conjunction with barbs 572 h ₁a to keep suture “S” (not shown)disposed in a substantially fixed position within the elongated headportion 572 h ₃ during operation of the anvil assembly 520.

According to further embodiments of the present disclosure, it iscontemplated that buttresses “B” may be provided or formed with integralwings or tabs extending therefrom for insertion and/or receipt intodistal and/or proximal recesses of anvil assembly and/or cartridgeassembly. It is further contemplated that sutures “S” may be affixed to,embedded in or other wise connected to buttresses “B.”

Exemplary surgical buttresses “B” for use with the surgical staplingdevices disclosed herein are shown and described in commonly assignedU.S. Pat. Nos. 5,542,594; 5,908,427; 5,964,774; and 6,045,560, andcommonly assigned U.S. application Ser. No. 12/579,605, filed on Oct.15, 2009 (now U.S. Patent Publication No. 2010/0092710, now U.S. Pat.No. 8,157,151), commonly assigned U.S. application Ser. No. 11/241,267,filed on Sep. 30, 2005 (U.S. Patent Publication No. 2006/0085034, nowU.S. Pat. No. 7,938,307), and U.S. application Ser. No. 11/248,846,filed on Oct. 12, 2005 (U.S. Patent Publication No. 2006/0135992, nowU.S. Pat. No. 7,823,592), the entire contents of each of which isincorporated herein by reference.

Surgical buttresses “B” may be fabricated from a suitable biocompatibleand bioabsorbable material. Surgical buttresses “B” may be fabricatedfrom a non-absorbent material which does not retain fluid. Surgicalbuttresses “B” may be fabricated from “BIOSYN” made from GLYCOMER 631 (ablock copolymer), a synthetic polyester composed of glycolide, dioxanoneand trimethylene carbonate.

One block of the resulting copolymer contains randomly combined unitsderived from p-dioxanone (1,4-dioxan-2-one) and trimethylene carbonate(1,3-dioxan-2-one). The second block of the copolymer contains randomlycombined units derived from glycolide and p-dioxanone. The resultingpolyester is an ABA triblock terpolymer possessing about 60% glycolide,about 14% dioxanone, and about 26% trimethylene carbonate.

In accordance with the present disclosure, it is further contemplatedthat surgical buttresses “B” may be constructed and/or fabricated, fromthe above-identified materials, as a non-woven, absorbable felt and thelike.

With reference to FIGS. 1-52, and specifically, FIGS. 51 and 52, asmentioned above, in accordance with the present disclosure, and eitherin place of or in addition to the methods and systems disclosed abovefor attaching surgical buttresses “B1, B2” to the tissuecontacting/facing surface of cartridge assembly 18 and/or anvil assembly20 of a surgical stapling apparatus 100, surgical buttresses “B1, B2”may be further attached to the tissue contacting/facing surface ofcartridge assembly 18 and/or anvil assembly 20 of surgical staplingapparatus 10 in a number of different ways.

For example, a roughness of a tissue facing side of surgical buttresses“B1, B2” may be minimized, thereby reducing friction between tissues andthe surgical buttresses “B1, B2” during tissue manipulation; a flexingof the surgical buttresses “B1, B2” between attachment points thereofmay be minimized, thereby limiting movement where the surgicalbuttresses “B1, B2” is not fastened to cartridge assembly 18 and/oranvil assembly 20; a shape of each surgical buttresses “B1, B2” may bemodified to conform to the topography of tissue facing surface ofcartridge assembly 18 and/or anvil assembly 20; and/or increase a widthof a profile of surgical buttresses “B1, B2” to be wider than a width ofthe respective cartridge assembly 18 and/or anvil assembly 20 widths sothat some lateral shifting of surgical buttresses “B1, B2” can occurwithout compromising reinforcement of the entire staple line.

Specifically, the surface roughness of the material of surgicalbuttresses “B1, B2” may be minimized by any number of means includingcalendaring, applying heat and pressure, adding a lubricious coating, orforming the material on a flat surface. In the case of melt blownsynthetic fabrics the material of surgical buttresses “B1, B2” could beproduced by blowing fibers onto a smooth heated belt to encouragerelaxation of the fibers to conform to the heated surface. Minimizingbuttress roughness reduces the interaction of the material of surgicalbuttresses “B1, B2” when being moved across tissue, thus reducing forcesexerted on the surgical buttresses “B1, B2” which lead to movement ofsurgical buttresses “B1, B2”.

Also, flexing or the flexibility of the material of surgical buttresses“B1, B2” may be minimized by increasing the material density, basisweight, or choosing a base material that has a high Young's modulus. Inthe case of melt blown synthetic fabrics, this can also be accomplishedby calendaring with heated rollers to increase intra fiber bonding andto increase fiber packing. Less material flexing equates to the surgicalbuttresses “B1, B2” moving less when forces are exerted thereon duringtissue manipulation.

Additionally, as seen in FIGS. 51 and 52, a topography of the surgicalbuttresses “B1, B2” may be shaped through heat and pressure when on therespective cartridge assembly 18 and/or anvil assembly 20, or staplereload, so that the surgical buttresses “B1, B2” conforms to the shapeof the tissue facing surface of the respective cartridge assembly 18and/or anvil assembly 20. This concept could include deforming thetopography of the surgical buttresses “B1, B2” through pressure with apatterned press in such a way that the material is slightly deformedlocally into the staple retaining pockets in the cartridge assembly 18and into the staple forming pockets on the anvil assembly 20 and alsointo the knife slots in the anvil assembly 20 and cartridge assembly 18.These local deformations would increase the contact area between thebuttress and cartridge and anvil surfaces and would thus make it moredifficult to displace the surgical buttresses “B1, B2” during tissuemanipulation.

Further, with continued reference to FIGS. 51 and 52, a profile of thesurgical buttresses “B1, B2” may be made wider so that its edges(lateral or otherwise) extend partially around the circumference andbeyond a lateral side edge of the respective cartridge assembly 18and/or anvil assembly 20, or staple reload. This could be done incombination with heat and pressure to ensure conformance of the materialof the surgical buttresses “B1, B2” to the tissue facing surface of therespective cartridge assembly 18 and/or anvil assembly 20 so thatshifting (i.e., lateral shifting) is hindered. Additionally, if anyshifting were to occur the extra width of the profiles of the surgicalbuttresses “B1, B2” would help ensure that the entire staple line isreinforced with buttress.

In addition to the foregoing, the surgical buttresses “B” may befabricated from any biodegradable and/or non-biodegradable material,including polymers, that can be used in surgical procedures. The term“biodegradable” as used herein is defined to include both bioabsorbableand bioresorbable materials. By biodegradable, it is meant that thematerial decomposes, or loses structural integrity under body conditions(e.g., enzymatic degradation or hydrolysis) or is broken down(physically or chemically) under physiologic conditions in the body,such that the degradation products are excretable or absorbable by thebody. Absorbable materials are absorbed by biological tissues anddisappear in vivo at the end of a given period, which can vary, forexample, from hours to several months, depending on the chemical natureof the material. It should be understood that such materials includenatural, synthetic, bioabsorbable, and/or certain non-absorbablematerials, as well as combinations thereof.

Representative natural biodegradable polymers which may be used to formthe medical devices include: polysaccharides such as alginate, dextran,chitin, chitosan, hyaluronic acid, cellulose, collagen, gelatin, fucans,glycosaminoglycans, and chemical derivatives thereof (substitutionsand/or additions of chemical groups including, for example, alkyl,alkylene, amine, sulfate, hydroxylations, carboxylations, oxidations,and other modifications routinely made by those skilled in the art);catgut; silk; linen; cotton; and proteins such as albumin, casein, zein,silk, soybean protein; and combinations such as copolymers and blendsthereof, alone or in combination with synthetic polymers.

Synthetically modified natural polymers which may be used to form themedical devices include cellulose derivatives such as alkyl celluloses,hydroxyalkyl celluloses, cellulose ethers, cellulose esters,nitrocelluloses, and chitosan. Examples of suitable cellulosederivatives include methyl cellulose, ethyl cellulose, hydroxypropylcellulose, hydroxypropyl methyl cellulose, hydroxybutyl methylcellulose, cellulose acetate, cellulose propionate, cellulose acetatebutyrate, cellulose acetate phthalate, carboxymethyl cellulose,cellulose triacetate, cellulose sulfate sodium salt, and combinationsthereof.

Representative synthetic biodegradable polymers which may be utilized toform medical devices include polyhydroxy acids prepared from lactonemonomers (such as glycolide, lactide, caprolactone, ε-caprolactone,valerolactone, and δ-valerolactone), carbonates (e.g., trimethylenecarbonate, tetramethylene carbonate, and the like), dioxanones (e.g.,1,4-dioxanone and p-dioxanone), 1,dioxepanones (e.g., 1,4-dioxepan-2-oneand 1,5-dioxepan-2-one), and combinations thereof. Polymers formedtherefrom include: polylactides; poly(lactic acid); polyglycolides;poly(glycolic acid); poly(trimethylene carbonate); poly(dioxanone);poly(hydroxybutyric acid); poly(hydroxyvaleric acid);poly(lactide-co-(ε-caprolactone-)); poly(glycolide-co-(ε-caprolactone));polycarbonates; poly(pseudo amino acids); poly(amino acids);poly(hydroxyalkanoate)s such as polyhydroxybutyrate,polyhydroxyvalerate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate),polyhydroxyoctanoate, and polyhydroxyhexanoate; polyalkylene oxalates;polyoxaesters; polyanhydrides; polyester anyhydrides; polyortho esters;and copolymers, block copolymers, homopolymers, blends, and combinationsthereof.

Synthetic degradable polymers also include hydrophilic vinyl polymersincluding phosphorylcholines such as 2-methacryloyloxyethylphosphorylcholine, hydroxamates, vinyl furanones and their copolymers,and quaternary ammonia; as well as various alkylene oxide copolymers incombination with other polymers such as lactones, orthoesters, andhydroxybutyrates, for example.

Rapidly bioerodible polymers, such as poly(lactide-co-glycolide)s,polyanhydrides, and polyorthoesters, which have carboxylic groupsexposed on the external surface as the surface of the polymer erodes,may also be used.

Other biodegradable polymers include polyphosphazenes; polypropylenefumarates; polyimides; polymer drugs such as polyamines; perfluoroalkoxypolymers; fluorinated ethylene/propylene copolymers; PEG-lactonecopolymers; PEG-polyorthoester copolymers; blends and combinationsthereof.

Some non-limiting examples of suitable nondegradable materials fromwhich the medical devices may be made include metals, ceramics, andpolymeric materials. Suitable nondegradable polymeric materials include,for example, polyolefins such as polyethylene (including ultra highmolecular weight polyethylene) and polypropylene including atactic,isotactic, syndiotactic, and blends thereof; polyethylene glycols;polyethylene oxides; polyisobutylene and ethylene-alpha olefincopolymers; fluorinated polyolefins such as fluoroethylenes,fluoropropylenes, fluoroPEGSs, and polytetrafluoroethylene; polyamidessuch as nylon, Nylon 6, Nylon 6,6, Nylon 6,10, Nylon 11, Nylon 12, andpolycaprolactam; polyimines; polyesters such as polyethyleneterephthalate, polyethylene naphthalate, polytrimethylene terephthalate,and polybutylene terephthalate; polyethers; polybutester;polytetramethylene ether glycol; 1,4-butanediol; polyurethanes; acrylicpolymers; methacrylics; vinyl halide polymers such as polyvinylchloride; polyvinyl alcohols; polyvinyl ethers such as polyvinyl methylether; polyvinylidene halides such as polyvinylidene fluoride andpolyvinylidene chloride; polychlorofluoroethylene; polyacrylonitrile;polyaryletherketones; polyvinyl ketones; polyvinyl aromatics such aspolystyrene; polyvinyl esters such as polyvinyl acetate;etheylene-methyl methacrylate copolymers; acrylonitrile-styrenecopolymers; ABS resins; ethylene-vinyl acetate copolymers; alkyd resins;polycarbonates; polyoxymethylenes; polyphosphazine; epoxy resins;aramids; rayon; rayon-triacetate; spandex; silicones; and copolymers andcombinations thereof.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, the stapling apparatus neednot apply staples but rather may apply two part fasteners as is known inthe art. Further, the length of the linear row of staples or fastenersmay be modified to meet the requirements of a particular surgicalprocedure. Thus, the length of a single stroke of the actuation shaftand/or the length of the linear row of staples and/or fasteners within adisposable loading unit may be varied accordingly. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended thereto.

What is claimed is:
 1. A method of securing a surgical buttress to atleast one of a cartridge assembly or an anvil assembly, the methodcomprising: applying a surgical buttress to a tissue facing surface ofat least one of a cartridge assembly or an anvil assembly; applyingpressure on the respective cartridge assembly or anvil assembly so thatthe surgical buttress conforms to the shape of the tissue facing surfaceby deforming the surgical buttress into staple retaining pockets and aknife slot of the cartridge assembly or staple forming pockets and aknife slot of the anvil assembly to which the surgical buttress isapplied, thereby increasing the contact area between the surgicalbuttress and the tissue facing surface.
 2. The method according to claim1, wherein the step of applying pressure includes applying pressure witha patterned press.
 3. The method according to claim 1, wherein applyingthe surgical buttress to the tissue facing surface further includesextending edges of the surgical buttress partially around acircumference of the cartridge assembly or the anvil assembly beyondlateral side edges of the tissue facing surface.
 4. The method accordingto claim 1, further comprising inserting first and second ends of afirst surgical suture into a distal pair of recesses defined in opposedsides of the cartridge assembly or the anvil assembly such that thefirst surgical suture extends across a distal portion of the surgicalbuttress.
 5. The method according to claim 4, further comprising movinga suture release assembly disposed within the cartridge assembly or theanvil assembly from an open configuration to a locking configuration tosecure the second end of the first surgical suture therein.
 6. Themethod according to claim 4, further comprising inserting first andsecond ends of a second surgical suture into a proximal pair of recessesdefined in opposed sides of the cartridge assembly or the anvil assemblysuch that the second surgical suture extends across a proximal portionof the surgical buttress.
 7. The method according to claim 1, whereinthe step of applying pressure comprises applying heat.
 8. A method ofsecuring a surgical buttress to a cartridge assembly or an anvilassembly, the method comprising: placing a surgical buttress on a tissuefacing surface of a cartridge assembly or an anvil assembly; anddeforming the surgical buttress into staple retaining pockets and aknife slot of the cartridge assembly or into staple forming pockets anda knife slot of the anvil assembly upon which the surgical buttress isplaced.
 9. The method according to claim 8, wherein deforming thesurgical buttress further includes applying heat to the surgicalbuttress.
 10. The method according to claim 8, wherein deforming thesurgical buttress further includes applying pressure to the surgicalbuttress.
 11. The method according to claim 10, wherein applyingpressure to the surgical buttress includes applying a patterned pressonto the surgical buttress.
 12. The method according to claim 8, furthercomprising reshaping the surgical buttress to conform to a topography ofthe tissue facing surface of the cartridge assembly or the anvilassembly.
 13. The method according to claim 8, wherein placing thesurgical buttress on the tissue facing surface further includesextending edges of the surgical buttress partially around acircumference of the cartridge assembly or the anvil assembly beyondlateral side edges of the tissue facing surface.
 14. The methodaccording to claim 8, further comprising inserting first and second endsof a surgical suture into a pair of recesses defined in opposed sides ofthe cartridge assembly or the anvil assembly such that the surgicalsuture extends across the surgical buttress.
 15. The method according toclaim 14, further comprising moving a suture release assembly disposedwithin the cartridge assembly or within the anvil assembly from an openconfiguration to a locking configuration to secure the second end of thesurgical suture therein.